org.modeshape.graph.request.processor
Class RequestProcessor

java.lang.Object
  org.modeshape.graph.request.processor.RequestProcessor

Direct Known Subclasses:

JcrRequestProcessor, LoggingRequestProcessor, MapRequestProcessor, PathRequestProcessor, Processor, SearchEngineProcessor

@NotThreadSafe
public abstract class RequestProcessor
extends Object

A component that is used to process and execute Requests. This class is intended to be subclassed and methods overwritten to define the behavior for executing the different kinds of requests. Abstract methods must be overridden, but non-abstract methods all have meaningful default implementations.

Nested Class Summary

protected class

RequestProcessor.LocationWithDepth A class that represents a location at a known depth

Constructor Summary

protected	RequestProcessor(String sourceName, ExecutionContext context, Observer observer)
protected	RequestProcessor(String sourceName, ExecutionContext context, Observer observer, DateTime now)
protected	RequestProcessor(String sourceName, ExecutionContext context, Observer observer, DateTime now, CachePolicy defaultCachePolicy)

Method Summary

protected int	absoluteMaximumDepthForBranchReads() This method is called from process(ReadBranchRequest) when determining the maximum depth for the subgraph.
void	close() Close this processor, allowing it to clean up any open resources.
protected void	completeRequest(Request request)
List<ChangeRequest>	getChanges() Obtain the list of ChangeRequests that were successfully processed by this processor.
protected CachePolicy	getDefaultCachePolicy()
ExecutionContext	getExecutionContext() The execution context that this process is operating within.
DateTime	getNowInUtc() Get the 'current time' for this processor, which is usually a constant during its lifetime.
String	getSourceName() Get the name of the source against which this processor is executing.
protected boolean	includeChildrenInSubgraph(Location location, Map<Name,Property> properties, boolean topOfSubgraph) This method is called from process(ReadBranchRequest) when determining whether particular nodes should be included in subgraph reads.
void	notifyObserverOfChanges() Take any of the changes that have been accumulated by this processor and notify the observer.
void	process(AccessQueryRequest request) Process a request to query a workspace with an access query, which is is a low-level atomic query that is part of a larger, planned query.
abstract void	process(CloneBranchRequest request) Process a request to clone a branch into a new workspace.
abstract void	process(CloneWorkspaceRequest request) Process a request to clone an existing workspace as a new workspace.
void	process(CollectGarbageRequest request) Process a request to collect garbage.
void	process(CompositeRequest request) Process a request that is composed of multiple other (non-composite) requests.
abstract void	process(CopyBranchRequest request) Process a request to copy a branch into another location.
abstract void	process(CreateNodeRequest request) Process a request to create a node at a specified location.
abstract void	process(CreateWorkspaceRequest request) Process a request to create a new workspace.
abstract void	process(DeleteBranchRequest request) Process a request to delete a branch at a specified location.
void	process(DeleteChildrenRequest request) Process a request to delete all of the child nodes under the supplied existing node.
abstract void	process(DestroyWorkspaceRequest request) Process a request to permanently destroy a workspace.
void	process(FullTextSearchRequest request) Process a request to search a workspace.
void	process(FunctionRequest functionRequest) Process a function request.
abstract void	process(GetWorkspacesRequest request) Process a request to get the information about the available workspaces.
void	process(LockBranchRequest request) Process a request to lock a node or branch within a workspace The default implementation of this method does nothing, as most connectors will not support locking.
abstract void	process(MoveBranchRequest request) Process a request to move a branch at a specified location into a different location.
abstract void	process(ReadAllChildrenRequest request) Process a request to read all of the children of a node.
abstract void	process(ReadAllPropertiesRequest request) Process a request to read the properties of a node at the supplied location.
void	process(ReadBlockOfChildrenRequest request) Process a request to read a block of the children of a node.
void	process(ReadBranchRequest request) Process a request to read a branch or subgraph that's below a node at a specified location.
void	process(ReadNextBlockOfChildrenRequest request) Process a request to read the next block of the children of a node, starting after a previously-retrieved child.
void	process(ReadNodeRequest request) Process a request to read the properties and children of a node at the supplied location.
void	process(ReadPropertyRequest request) Process a request to read a single property of a node at the supplied location.
void	process(RemovePropertyRequest request) Process a request to remove the specified property from a node.
void	process(RenameNodeRequest request) Process a request to rename a node specified location into a different location.
void	process(Request request) Process a request by determining the type of request and delegating to the appropriate process method for that type.
void	process(SetPropertyRequest request) Process a request to set the specified property on a node.
void	process(UnlockBranchRequest request) Process a request to unlock a node or branch within a workspace The default implementation of this method does nothing, as most connectors will not support locking.
abstract void	process(UpdatePropertiesRequest request) Process a request to remove the specified properties from a node.
void	process(UpdateValuesRequest request) Process a request to add and/or remove the specified values from a property on the given node.
void	process(VerifyNodeExistsRequest request) Process a request to verify that a node exists at the supplied location.
abstract void	process(VerifyWorkspaceRequest request) Process a request to verify a named workspace.
protected void	processUnknownRequest(Request request) Method that is called by process(Request) when the request was found to be of a request type that is not known by this processor.
protected void	recordChange(ChangeRequest request) Record the supplied change request for publishing through the event mechanism.
protected void	setCacheableInfo(CacheableRequest request) Set the supplied request to have the default cache policy and the current time in UTC.
protected void	setCacheableInfo(CacheableRequest request, CachePolicy cachePolicy) Set the supplied request to have the supplied cache policy and the current time in UTC.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

RequestProcessor

protected RequestProcessor(String sourceName,
                           ExecutionContext context,
                           Observer observer)

RequestProcessor

protected RequestProcessor(String sourceName,
                           ExecutionContext context,
                           Observer observer,
                           DateTime now)

RequestProcessor

protected RequestProcessor(String sourceName,
                           ExecutionContext context,
                           Observer observer,
                           DateTime now,
                           CachePolicy defaultCachePolicy)

Method Detail

recordChange

protected void recordChange(ChangeRequest request)

Record the supplied change request for publishing through the event mechanism.

Parameters:

request - the completed change request; may not be null, and may not be cancelled or have an error

getSourceName

public final String getSourceName()

Get the name of the source against which this processor is executing.

Returns:

the repository source name; never null or empty

getExecutionContext

public final ExecutionContext getExecutionContext()

The execution context that this process is operating within.

Returns:

the execution context; never null

getNowInUtc

public final DateTime getNowInUtc()

Get the 'current time' for this processor, which is usually a constant during its lifetime.

Returns:

the current time in UTC; never null

getDefaultCachePolicy

protected final CachePolicy getDefaultCachePolicy()

Returns:

defaultCachePolicy

setCacheableInfo

protected void setCacheableInfo(CacheableRequest request)

Set the supplied request to have the default cache policy and the current time in UTC.

Parameters:

request - the cacheable request

setCacheableInfo

protected void setCacheableInfo(CacheableRequest request,
                                CachePolicy cachePolicy)

Set the supplied request to have the supplied cache policy and the current time in UTC.

Parameters:

request - the cacheable request

cachePolicy - the cache policy for the request; may be null if there is to be no cache policy

process

public void process(Request request)

Process a request by determining the type of request and delegating to the appropriate process method for that type.

This method does nothing if the request is null.

Parameters:

request - the general request

completeRequest

protected void completeRequest(Request request)

process

public void process(CompositeRequest request)

Process a request that is composed of multiple other (non-composite) requests. If any of the embedded requests has an error after it is processed, each of the embedded requests will be marked with the error and the submitted composite request will be marked with an error. If one of the embedded requests attempts to make a change and results in an error, then the processing of all remaining embedded requests is aborted and the composite request will be marked with only this error from the change request.

This method does nothing if the request is null.

Parameters:

request - the composite request

processUnknownRequest

protected void processUnknownRequest(Request request)

Method that is called by process(Request) when the request was found to be of a request type that is not known by this processor. By default this method sets an unsupported request error on the request.

Parameters:

request - the unknown request

process

public abstract void process(VerifyWorkspaceRequest request)

Process a request to verify a named workspace.

This method does nothing if the request is null.

Parameters:

request - the request

process

public abstract void process(GetWorkspacesRequest request)

Process a request to get the information about the available workspaces.

This method does nothing if the request is null.

Parameters:

request - the request

process

public abstract void process(CreateWorkspaceRequest request)

Process a request to create a new workspace.

This method does nothing if the request is null.

Parameters:

request - the request

process

public abstract void process(CloneBranchRequest request)

Process a request to clone a branch into a new workspace.

This method does nothing if the request is null.

Parameters:

request - the request

process

public abstract void process(CloneWorkspaceRequest request)

Process a request to clone an existing workspace as a new workspace.

This method does nothing if the request is null.

Parameters:

request - the request

process

public abstract void process(DestroyWorkspaceRequest request)

Process a request to permanently destroy a workspace.

This method does nothing if the request is null.

Parameters:

request - the request

process

public abstract void process(CopyBranchRequest request)

Process a request to copy a branch into another location.

This method does nothing if the request is null.

Parameters:

request - the copy request

process

public abstract void process(CreateNodeRequest request)

Process a request to create a node at a specified location.

This method does nothing if the request is null.

Parameters:

request - the create request

process

public abstract void process(DeleteBranchRequest request)

Process a request to delete a branch at a specified location.

This method does nothing if the request is null.

Parameters:

request - the delete request

Throws:

ReferentialIntegrityException - if the delete could not be performed because some references to deleted nodes would have remained after the delete operation completed

process

public void process(DeleteChildrenRequest request)

Process a request to delete all of the child nodes under the supplied existing node.

This method does nothing if the request is null.

Parameters:

request - the delete request

Throws:

ReferentialIntegrityException - if the delete could not be performed because some references to deleted nodes would have remained after the delete operation completed

process

public abstract void process(MoveBranchRequest request)

Process a request to move a branch at a specified location into a different location.

This method does nothing if the request is null.

Parameters:

request - the move request

process

public abstract void process(ReadAllChildrenRequest request)

Process a request to read all of the children of a node.

This method does nothing if the request is null.

Parameters:

request - the read request

process

public void process(ReadBlockOfChildrenRequest request)

Process a request to read a block of the children of a node. The block is defined by a starting index and a maximum number of children to include in the block.

This method does nothing if the request is null. The default implementation converts the command to a ReadAllChildrenRequest, and then finds the children within the block. Obviously for large numbers of children, this implementation may not be efficient and may need to be overridden.

Parameters:

request - the read request

process

public void process(ReadNextBlockOfChildrenRequest request)

Process a request to read the next block of the children of a node, starting after a previously-retrieved child.

This method does nothing if the request is null. The default implementation converts the command to a ReadAllChildrenRequest, and then finds the children within the block. Obviously for large numbers of children, this implementation may not be efficient and may need to be overridden.

Parameters:

request - the read request

process

public void process(ReadBranchRequest request)

Process a request to read a branch or subgraph that's below a node at a specified location.

This method does nothing if the request is null. The default implementation processes the branch by submitting the equivalent requests to read the nodes and the children. It starts by doing this for the top-level node, then proceeds for each of the children of that node, and so forth.

Parameters:

request - the request to read the branch

absoluteMaximumDepthForBranchReads

protected int absoluteMaximumDepthForBranchReads()

This method is called from process(ReadBranchRequest) when determining the maximum depth for the subgraph. By default, this method returns Integer.MAX_VALUE, signaling that the ReadBranchRequest's maximum depth should be honored. However, subclasses can override this method to return a constant value that will be used if less than the ReadBranchRequest's maximum depth.

Returns:

the maximum read depth allowed by the processor; must be positive

includeChildrenInSubgraph

protected boolean includeChildrenInSubgraph(Location location,
                                            Map<Name,Property> properties,
                                            boolean topOfSubgraph)

This method is called from process(ReadBranchRequest) when determining whether particular nodes should be included in subgraph reads. For example, some processor implementations might want to always exclude nodes with certain names from all subgraph reads. If this is the case, subclasses should override this method (which always returns true), and determine whether the node at the supplied location should be included in the subgraph.

Parameters:

location - the location of the parent node; never null

properties - the properties of the parent node; never null

topOfSubgraph - true if the parent node (identified by the location) is the root of the subgraph

Returns:

true if the child nodes should be read and included in the subgraph, or false otherwise

process

public abstract void process(ReadAllPropertiesRequest request)

Process a request to read the properties of a node at the supplied location.

This method does nothing if the request is null.

Parameters:

request - the read request

process

public void process(ReadNodeRequest request)

Process a request to read the properties and children of a node at the supplied location.

This method does nothing if the request is null. Unless overridden, this method converts the single request into a ReadAllChildrenRequest and a ReadAllPropertiesRequest.

Parameters:

request - the read request

process

public void process(ReadPropertyRequest request)

Process a request to read a single property of a node at the supplied location.

This method does nothing if the request is null. Unless overridden, this method converts the request that reads the node and simply returns the one property.

Parameters:

request - the read request

process

public void process(VerifyNodeExistsRequest request)

Process a request to verify that a node exists at the supplied location.

This method does nothing if the request is null. Unless overridden, this method converts the request that reads the node and uses the result to determine if the node exists.

Parameters:

request - the read request

process

public void process(RemovePropertyRequest request)

Process a request to remove the specified property from a node.

This method does nothing if the request is null. Unless overridden, this method converts this request into a UpdatePropertiesRequest.

Parameters:

request - the request to remove the property

process

public void process(SetPropertyRequest request)

Process a request to set the specified property on a node.

This method does nothing if the request is null. Unless overridden, this method converts this request into a UpdatePropertiesRequest.

Parameters:

request - the request to set the property

process

public abstract void process(UpdatePropertiesRequest request)

Process a request to remove the specified properties from a node.

This method does nothing if the request is null.

Parameters:

request - the remove request

process

public void process(UpdateValuesRequest request)

Process a request to add and/or remove the specified values from a property on the given node.

This method does nothing if the request is null.

Parameters:

request - the remove request

process

public void process(RenameNodeRequest request)

Process a request to rename a node specified location into a different location.

This method does nothing if the request is null. Unless overridden, this method converts the rename into a move. However, this only works if the request has a path for its location. (If not, this method throws an UnsupportedOperationException and must be overridden.)

Parameters:

request - the rename request

process

public void process(LockBranchRequest request)

Process a request to lock a node or branch within a workspace

The default implementation of this method does nothing, as most connectors will not support locking. Any implementation of this method should do nothing if the request is null.

Implementations that do support locking should throw a LockFailedException if the request could not be fulfilled.

Parameters:

request - the request

process

public void process(UnlockBranchRequest request)

Process a request to unlock a node or branch within a workspace

The default implementation of this method does nothing, as most connectors will not support locking. Any implementation of this method should do nothing if the request is null.

Parameters:

request - the request

process

public void process(AccessQueryRequest request)

Process a request to query a workspace with an access query, which is is a low-level atomic query that is part of a larger, planned query.

The default implementation of this method behaves as though the implementation does not support queries by setting an error on the request

Parameters:

request - the request

process

public void process(FullTextSearchRequest request)

Process a request to search a workspace.

The default implementation of this method behaves as though the implementation does not support full-text searches by setting an error on the request

Parameters:

request - the request

process

public void process(CollectGarbageRequest request)

Process a request to collect garbage.

The default implementation of this method does nothing.

Parameters:

request - the request

process

public void process(FunctionRequest functionRequest)

Process a function request.

The default implementation applies the function.

Parameters:

functionRequest - the request

close

public void close()

Close this processor, allowing it to clean up any open resources.

getChanges

public List<ChangeRequest> getChanges()

Obtain the list of ChangeRequests that were successfully processed by this processor.

Note that this list is modified during processing and thus should only be accessed by the caller when this processor has been closed.

Also, if this processor encounters errors while processing change requests, the processor does not throw out any of the changes. Thus it is up to the caller to decide whether any of the changes are to be kept.

Returns:

the list of successful changes; never null but possibly empty.

notifyObserverOfChanges

public void notifyObserverOfChanges()

Take any of the changes that have been accumulated by this processor and notify the observer. This should only be called after close() has been called.